Speaker amplifier



E. A. ROCKWELL SPEAKER AMPLIFIER Filed April 16, 1932 2 Sheets-Sheet l lNVENTOR ;c t1.=3l,1933. E. A. ROCKWELL 1,932,460

SPEAKER AMPLIFIER Filed April 16, 1932 2 Sheets-Sheet 2 INVENTOR ATTORNEY.

Patented a. 31; 1933 1,932,460

UNITED STATES PATENT OFFICE SPEAKER AMPLIFIER Edward A. Rockwell, Chicago, Ill., assignor to Patent Engineering Corporation, a corporation of Delaware Application April 16, 1932. Serial No. 605,568 12 Claims. (Cl. 179-1) This invention relates to improvements in held Within the magnetic field of the field coil 11.

speaker amplifiers and has for an object the pro-' A flexible arm 16 is also secured to the cone vision of means for efiecting regeneration at adjacent to the voice coil and is secured to a audio frequencies. boss 17 on the frame 12 in any suitable manner '5 Another object of the invention is to generate such as by a screw 18.

a series of impulses by means of the motion of a A crystal 19 which may be of any material havmoving part of a loud speaker. ing piezo-electric qualities such as quartz or ro- A further object of the invention is to superchelle salt, etc. has metallic sheets or plates 20 impose generated impulses directly controlled by and 21 secured to the sides thereof and connected ill) the motion of a loud speaker, upon the same amto the lead wires 22 and 23 respectively. plifier which furnishes the original impulses, A clamp bracket 24 is rigidly secured to one thereby obtaining a gain inthe volume of sound end of the crystal 19 and is mounted on the frame reproduced by the speaker. 12 by means of screws or rivets 25.

Other objects and advantages of the invention A second bracket 26 is clamped to the other :15) will be apparent to those skilled in the art. end of the crystal 19 and an extended arm 27 In loud speaker systems where a large volume thereof is secured to the flexible arm 16 by a of sound is required it has heretofore been necesrivet 28 or any other suitable means. sary to provide powerful amplifiersfor use there- When the loud speaker is operated the flexible with utilizing larger and more costly tubes and arm l6 vibrates and at the same time themotion 20 the portability of such amplifiers is limited due of the arm 16 is imparted to the end of the crystal to the size thereof and the weight of the elements 19 via the clamp bracket 26. Since the other end therein. a i of the crystal has its clamp 24 rigidly secured to In the present invention, an ordinary amplifier the frame 12 the crystal19 is fiexed and a voltage is used and a crystal is provided and driven by is generated, the impulses .thereof being in time '25 a moving part of the speaker and the voltage relation to the movement of the moving element 50 a field coil 11 supported on a suitable frame 12. ages to be generated by the crystal 19 and these generated by the crystal (due to the fiexingthereof the loud speaker.

of) is fed back into the amplifier and the ampli- By superimposing this voltage upon the input fied voltage impulses are thereby impressed upon of the amplifier portion of a radio receiver an the speaker along with the signal impulses. This increase in output is obtained giving a regenera- 30 causes the speaker to vibrate with still greater tive eiiect. motion (and sound) thereby generating greater A diagram showing connections for obtaining motion and hence higher voltage impulses in this eiiect is shown in Figure 3 in which the ele the crystal and so on until a maximum volume ments are shown conventionally. of sound is obtained, eiiecting an audio frequency The cone 14 with its attached voice coil 15 35 regeneration in the amplifier. This is accomunder the influence of the field 11 are shown, and 90 plished with smaller elements in the amplifier the crystal 19 is moved by the moving part of the unit for the same output than heretofore. speaker. A

Referring to the drawings: The lead 22 is connected to ground and the Figure 1 is a side elevation of a loud speaker lead 23 is connected via a condenser 31 to the in- 40 comprising one embodiment of the invention; put of the first audio frequency amplifier tube Figure 2 is a section of the device in Figure l thereby the impulses generated y the ys along the line 2-2; and 19 are superimposed upon the control element 32,

Figure 3 is a circuit suitable for use with the amplified by the first stage 33 and further amplidevice and showing one method of connecting fied by the push-pull stage 34. 45 the crystal to the amplifier portion of the circuit. This addition of the superimposed impulses to 0 In one embodiment of the invention a dynamic the primary impulses or signals rectified by the speaker is shown but it is obvious that any type detector 29 and passing through the amplifier of speaker may be used. 30, 34 causes still greater movement of the mov- This speaker designated by the numeral 10 has ing element of the speaker, causing greater volt- An annular ring 13 carried by the frame 12 greater impulses passing through the amplifier serves as a support for the outer edge of the cone giving a regenerative effect and a substantial in- 14. i crease in the volume of the speaker is efiected A voice coil 15 is'secured to or made integral without the necessity of additional electronic 55 with the smaller end of the cone and. is thereby stages in the amplifier.

While a simple embodiment of the invention is herein shown and described it is obvious that many changes may be made without departing from the scope of the invention as defined in the following claims.

What is claimed is:

1. The herein described method of effecting regeneration which consists of amplifying sig-- nals in an electron tube amplifier, reproducing the amplified signals by means of a loud speaker, flexing a fixed piezo-electric crystal by the movement of saidspeaker thereby causin the crystal to generate electrical impulses in timed relation to said signals, and passing said impulses through said amplifier along with the signals passing therethrough.

2. A loud speaker comprising a moving element and means for vibrating the same, and a fixed piezo-electric crystal separate from said means associated with said speaker and adapted to be flexed by the movement of said speaker.

3. A loud speaker comprising a frame, a moving element and means for vibrating the same mounted on said frame. and a crystal separate from said moving element having one end rigidly secured to said frame and the other end operatively connected to a moving part of said speaker and adapted to move therewith.

4. A loud speaker having a frame and a moving element adapted to reproduce signals, means for moving said element and a crystal supported by said frame and driven by said element adapted to generate impulses in timed relation to the movement of said element, said crystal being separate from said means.

5. A loud speaker having a frame, a moving element carried by said frame, a stationary element mounted on theframe for moving said first element, and a crystal separate from said stationary element having one end rigidly secured to the frame and its other end driven by the moving element.

6. A loud speaker having a frame, a moving element carried by said frame, a stationary element mounted on the frame for moving said first element, an arm having one end secured to the moving element and the other end secured to the frame, and a crystal separate from said stationary element having one end rigidly secured to the frame and the other end secured to said arm.

7. A loud speaker havinga frame, a moving element carried by said frame, a stationary element mounted on the frame for moving said first element, a flexible arm having one end secured t0 and adapted to be flexed by the moving ele ment and the other end secured to the frame, and

a crystal separate from said stationary element having one end rigidly secured to the frame and the other end adapted to be moved synchronously 851) with the flexing of said arm.

8. In combination a magnetic device having a frame, a crystal having a portion rigidly fixed to said frame and having a portion adapted to be flexed by said magnetic device, and means for amplifying impulses generated by said crystal due to the flexing thereof.

9. In combination an amplifier, a magnetic device having a frame connected thereto, a crystal having a portion rigidly fixed to said frame and having a portion adapted to be flexed by said device, and means connecting said crystal to the input end of said amplifier whereby impulses generated by said crystal due to the flexing thereof are amplified along with signals passing therethrough and regeneration is effected.

10. In combination an amplifier, a loud speaker connected to said amplifier, a piezo-electric crystal adapted to be moved by said speaker when 1100 actuated by signals passing through said amplifier, and means for superimposing impulses generated by said crystal upon signals entering said amplifier, whereby a regenerative action is attained and all signals entering said amplifier are amplified therein in proportion to the movement of said crystal.

11. In combination an amplifier having input and output stages, a loud speaker connected to said output stage, a signal translating device 1m connected to the input stage, a crystal adapted to be flexed by movement of said speaker, and means connecting said crystal to said input stage, whereby a regenerative action is attained and all signals entering said amplifier are amplified 1115 therein in proportion to the movement of said crystal.

12. In combination an amplifier having a plurality of electronic stages including input and output stages, a loud speaker connected to said output stage, a signal translating device connected to the input stage, a crystal adapted to be flexed by movement of said speaker, and means conmeeting said crystal to one of said stages, whereby a regenerative action is attained and all signals entering said amplifier are amplified therein in proportion to the movement of said crystal.

mWARD A. ROCKWELL. 

